Histogram Analysis of Diffusion Kurtosis Magnetic Resonance Imaging for Diagnosis of Hepatic Fibrosis

OBJECTIVE: To investigate the diagnostic value of diffusion kurtosis imaging (DKI) histogram analysis in hepatic fibrosis staging. MATERIALS AND METHODS: Thirty-six rats were divided into carbon tetrachloride-induced fibrosis groups (6 rats per group for 2, 4, 6, and 8 weeks) and a control group (n = 12). MRI was performed using a 3T scanner. Histograms of DKI were obtained for corrected apparent diffusion (D), kurtosis (K) and apparent diffusion coefficient (ADC). Mean, median, skewness, kurtosis and 25th and 75th percentiles were generated and compared according to the fibrosis stage and inflammatory activity. RESULTS: A total of 35 rats were included, and 12, 5, 5, 6, and 7 rats were diagnosed as F0–F4. The mean, median, 25th and 75th percentiles, kurtosis of D map, median, 25th percentile, skewness of K map, and 75th percentile of ADC map demonstrated significant correlation with fibrosis stage (r = −0.767 to 0.339, p < 0.001 to p = 0.039). The fibrosis score was the independent variable associated with histogram parameters compared with inflammatory activity grade (p < 0.001 to p = 0.041), except the median of K map (p = 0.185). Areas under the receiver operating characteristic curve of D were larger than K and ADC maps in fibrosis staging, although no significant differences existed in pairwise comparisons (p = 0.0512 to p = 0.847). CONCLUSION: Corrected apparent diffusion of DKI histogram analysis provides added value and better diagnostic performance to detect various liver fibrosis stages compared with ADC.

Bone morphogenetic protein-2/type I collagen hydrogels for anterior cruciate ligament injury / 中国组织工程研究

BACKGROUND: No conclusion has yet been drawn on the effect of bone morphogenetic protein-2 (BMP-2)/collagen type I hydrogels on tendon-bone healing during the reconstruction of anterior cruciate ligament (ACL) is inconclusive. OBJECTIVE: To investigate the effect of BMP-2/collagen type I hydrogels to repair ACL injury. METHODS: ACL injury models were made in the right knees of 18 New Zealand rabbits. Model rabbits were randomized into three groups: blank control group with no intervention, control group with implantation of autologous semitendinosus tendon into the tibial and femoral tunnels, and experimental group with implantation of autologous semitendinosus tendon into the tibial and femoral tunnels combined with BMP-2/collagen type I hydrogel injection into the tibial tunnel. The Micro-CT, hematoxylin-eosin staining and Masson staining of the tendon-bone interface were conducted at 3 months after implantation. RESULTS AND CONCLUSION: (1) Micro-CT imaging examination: No obvious bone tissue regeneration around the tibial tunnel (at the opening site, 1 cm distant to the opening site, and at the widest site of the tunnel) was observed in the blank control group. Discontinuous bone regeneration in the tibial tunnel was found in the control group. In the experimental group, there was obvious tendon-bone regeneration and continuous bone connections in part of the tibial tunnel. (2) Hematoxylin-eosin staining: In the blank control group, sparse fibrous tissue and regenerated bone tissue were observed in the bone tunnel. In the control group, new bone tissues grew into the tendon, but the tendon and the surrounding tissue were loose, with a large amount of fibrocytes and the small new bone area. In the experimental group, a large number of new bone tissues were regenerated in the tendon, the tendon was intertwined with the surrounding bone tissues, and the area of new bone was increased. (3) Masson staining: In the blank control group the tunnel was partially filled with fat or fibrous tissues, and no tendon-bone interface appeared. In the control group, cartilage and fibrous tissues were visible on the tendon-bone interface, but the fibrous tissues were loosely arranged and had no close connection with the cartilage tissues. In the experimental group, fibrous-chondral-bone tissues were found on the tendon-bone interface, with fibrous tissues being tightly bound to the cartilage tissues, and mature bone tissues were visible below the cartilage tissue. These results indicate that BMP-2/collagen type I hydrogel is beneficial to ACL repair by strengthening the bone regeneration in the bone tunnel and the healing of tendon-bone junction.

Application of computed tomography virtual noncontrast spectral imaging in evaluation of hepatic metastases: a preliminary study / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>The objective was to qualitatively and quantitatively evaluate hepatic metastases using computed tomography (CT) virtual noncontrast (VNC) spectral imaging in a retrospective analysis.</p><p><b>METHODS</b>Forty hepatic metastases patients underwent CT scans including the conventional true noncontrast (TNC) and the tri-phasic contrast-enhanced dual energy spectral scans in the hepatic arterial, portal venous, and equilibrium phases. The tri-phasic spectral CT images were used to obtain three groups of VNC images including in the arterial (VNCa), venous (VNCv), and equilibrium (VNCe) phase by the material decomposition process using water and iodine as a base material pair. The image quality and the contrast-to-noise ratio (CNR) of metastasis of the four groups were compared with ANOVA analysis. The metastasis detection rates with the four nonenhanced image groups were calculated and compared using the Chi-square test.</p><p><b>RESULTS</b>There were no significant differences in image quality among TNC, VNCa and VNCv images (P > 0.05). The quality of VNCe images was significantly worse than that of other three groups (P < 0.05). The mean CNR of metastasis in the TNC and VNCs images was 1.86, 2.42, 1.92, and 1.94, respectively; the mean CNR of metastasis in VNCa images was significantly higher than that in other three groups (P < 0.05), while no statistically significant difference was observed among VNCv, VNCe and TNC images (P > 0.05). The metastasis detection rate of the four nonenhanced groups with no statistically significant difference (P > 0.05).</p><p><b>CONCLUSIONS</b>The quality of VNCa and VNCv images is identical to that of TNC images, and the metastasis detection rate in VNC images is similar to that in TNC images. VNC images obtained from arterial phase show metastases more clearly. Thus, VNCa imaging may be a surrogate to TNC imaging in hepatic metastasis diagnosis.</p>

Synthesis of phenyloxyisobutyric acid derivatives and their antidiabetic activity in vitro / 药学学报

<p><b>AIM</b>To design and synthesize new phenyloxyisobutyric acid analogues as antidiabetic compounds.</p><p><b>METHODS</b>Eight new target compounds were synthesized by combination of lipophilic moieties and acidic moiety with nucleophilic replacement or Mitsunobu condensation. The eight compounds were confirmed by 1H NMR, 13C NMR, IR and MS.</p><p><b>RESULTS</b>In vitro insulin-sensitizing activity (3T3-L1 adipocyte) demonstrated, that the cultured glucose concentration of up-clear solution detected with GOD-POD assay were 5.942, 6.339, 6.226 and 6.512 mmol x L(-1), respectively, when rosiglitazone, pioglitazone, compounds A and B were added to the insulin-resistant system.</p><p><b>CONCLUSION</b>In vitro insulin-sensitizing activity of target compound A is in between that of rosiglitazone and pioglitazone, and activity of target compound B is slightly less than that of pioglitazone.</p>